The present invention relates to a suspension mechanism in automatic washing machines with horizontal axis, loaded from the front or from the top, providing the positioning of the tub (2) and its vibratory movement in the cabinet (1).
Automatic washing machines are electrical appliances wherein the clothes loaded into a cylindirical drum (3) are washed by the agitation/fluctuations created by the rotation of the drum (3). The basic functions of the machine such as water and detergent intake, washing, rinsing, spindrying and water discharge are performed automatically and according to a predetermined program. Washing machines with horizontal axis are characterized in that the rotational axis of the drum (3) wherein the laundry is loaded, is parallel or inclined at an angle smaller than 45xc2x0 to the ground. There are two major types of automatic washing machines with horizontal axis, with regard to the location of the loading door, namely front-loading and top-loading machines. In the front-loading machines with horizontal axis, the opening axis of the loading door is perpendicular to the axis of the drum (3) rotary axis and it is perpendicular or at some angle to the floor in front of the cabinet (1), depending on whether the drum (3) rotary axis is parallel or at a certain angle to the floor. Whereas in the top-loading horizontal axis machines, the door is on top of the cabinet (1) and its opening axis is parallel to and above the drum (3) rotary axis.
The tub assembly comprising the drum (3) vibrates due to the non-uniform and unbalanced distribution of the laundry in the drum (3) because of such processes as inserting the clothes in the water and taking them out, and dropping them down from certain heights with the rotary motion of the drum (3) during the washing cycle and the laundry taking a lumpy form during rinsing and spinning operations. The suspension mechanism is an arrangement consisting of such components as springs (4), dampers (5) and the like, to be used for the purpose of damping (suppressing) these vibrations and transferring them to the cabinet (1) of the machine so that the user will not be disturbed.
The components making up the automatic washing machines with horizontal axis can be classified in general terms as: a cabinet (1), moving tub (2) assembly, suspension mechanism and water connection parts.
The cabinet (1) is provided with the detergent dispenser, control panel, laundry loading door, pump, water inlet and outlet hoses. As mentioned above, the laundry loading door is in front of the cabinet (1) in front-loading machines and is on top of the cabinet (1) in top-loading machines.
The moving tub assembly consists of; a drum (2), counter weights fixed on the drum (2), a roller bearing at the rear surface of the tub (2), a cylindrical shaft passing through the said roller bearing and making rotating movement, a flange fixed to this shaft, a geometrically symmetric drum (3) connected to the shaft by means of the said flange, a heater placed between the outer surface of the drum (3) and the inner surface of the tub (2), an electrical motor mounted below or behind the tub (2) or in the roller bearing, moment transmission components such as belt, pulley, gear assembly, etc., providing the transmission of the motor movement to the shaft-flange-drum group. The drum (3) rotates around its axis of symmetry, by means of these moment transmission components in case the motor is below the tub (2), and by means of the rotative movement transmitted directly to the shaft, in case it is above the roller bearing. On the inner surface of the drum (3) wherein the laundry is loaded, are a plurality of baffles and on its outer surface are a plurality of small holes/piercings. In some machines, on the front and/or rear surfaces there are balancing components with moving small masses therein.
The moving tub assembly making vibratory movements in the machine, is connected to the cabinet (1) by means of a suspension mechanism consisting of such components as spring (4) and damper (5). In the suspension mechanisms formed by the conventional technique, one or more spring (s) [4] and/or damper (s) [5]; and/or spring-damper which functions as spring and damper, are used. By means of elastic bellow, placed on the body (1) between the loading door and the front surface of the tub, water is retained in the tub (2), prevented to leak out of the tub (2) during the operation of the machine.
Washing is a process provided by the rotational movements of the drum (3) to left or to right, and by its stopping and waiting for a certain period without rotating, after controlling such parameters as direction, speed, time period, angle of rotation; amount, type, temperature of the washing water; type, amount of chemical cleaning agents are controlled. During this process, the rotative speed of the drum (3) is such that it will not allow the laundry within the drum are spinned on the wall of the drum due to the centrifugal force and rotate together with the drum. The baffles on the inner surfaces of the drum (3) provide the movement, raising and dropping and tumbling of the laundry inside the drum during washing and can also serve to circulate the water within the drum.
During the rinsing cycle, following the washing cycle, generally the drum (3) will rotate together with the laundry it contains, under the effect of centrifugal force: however it is rotated at low speeds so that an excessive imbalance will not be created because of the high amount of water. During this process an important portion of water remained in the laundry is discharged into the tub (2) under the effect of the centrifugal forces created by the rotation of the drum (3), out of the drum holes. Controls are made in order to determine the rotational speed of the drum (3) wherein a high speed spinning will be realized.
After the completion of washing and rinsing phases, during the spinning cycle some more of the remaining water in the drum is discharged into the tub (2) through the drum (3) holes, due to the high centrifugal forces created by the high speed rotation of the drum. Then water accumulated in the tub (2) is evacuated from the machine by means of a pump and the water discharge hose.
In the patent application No. EP 0 655 111 system consisting of metal cables with elastic, anti-impact and anti-vibration properties developed for supporting a rotary unit within a fixed frame, is explained. However, this system is completely different from the invention disclosed in this application in such points as its being metallic, its being connected to the tub and body at a single point and its basically functioning as a spring.
The tub assembly including the drum (3) makes vibratory movements in the cabinet (1) in the washing cycle during the rotation of the drum, due to the immersion of the laundry into the washing water and taking it out and to the dropping of the laundry from certain heights within the drum i.e tumbling of the laundry: and in rinsing and spinning cycles, the non-uniform distribution of the laundry taking lumpy forms within the drum (3).
In the known suspension mechanisms; the resistance parameters of the springs (4) and damping parameters of the dampers (5), taken into consideration together with weight of the moving tub assembly and the resistance and/or damping parameters of such components as the bellows placed between the tub assembly (2) and the cabinet (1), or water hoses etc., should be xe2x80x9crigidxe2x80x9d enough so that the tub assembly can easily make vibratory movements without hitting the fixed components, but it should also be xe2x80x98softxe2x80x99 enough to transmit the forces created due to vibration without causing the cabinet (1) to move on the floor. In other words, a xe2x80x9ctoo rigidxe2x80x9d suspension mechanism decreases the vibration of the tub assembly but increases the possibility of the cabinet (1) moving on the floor whereas a too xe2x80x98softxe2x80x99 suspension mechanism reduces the possibility of its moving oil the floor but causes an increase in the vibratory movements of the tub assembly and subsequently the possibility of hitting the fixed components.
Another parameter defining the resistance/damping properties of the suspension mechanism and preventing it from being xe2x80x9ctoo softxe2x80x9d is the necessity of preventing the tub assembly from sinking too much into the cabinet (1) and consequently preventing the centers of the drum (3) rotational axis and the laundry loading gate on top of the cabinet (1) from being differentiated. In such a case, the rubber bellow-like gasket placed between the laundry loading gate and the drum (3) will be worn out and/or will draw the resistance/damping parameters of the suspension mechanism to unwanted levels due to its excessive deformation.
The objective of the present invention is to provide the suspension of the tub assembly in such a manner that it can vibrate freely in the body, by using the elastic bands (6) instead of the suspension mechanism components such as spring (4), damper (5) etc. that arc used in the conventional systems or together with them. The required resistance and damping parameters are obtained by sizing the bands (6) appropriately, by the elasticity of the bands and (or by their reciprocal movements with friction on the tub (2) as shown in FIG. 6, consequently the vibrations of the tub assembly are suppressed and transmitted to the fixed exterior cabinet (1) of the machine so that they would not disturb the user.
Another objective of the present invention is to make the suspension mechanism xe2x80x9csofterxe2x80x9d than the stiffness degree implemented by the existing technique, in other words, to reduce the resistance/damping parameters of the suspension mechanism, with or without the suspension mechanism components such as spring (4), damper (5) etc. that are used in the conventional systems, so that the bellow component located between the loading door and the drum (3) will not be worn off and it will not draw the resistance/damping parameters of the suspension mechanism to unwanted levels due to its excessive deformation. In this way the impact of the tub assembly to the fixed components will be prevented and it will be possible to reduce the movement of the cabinet (1) on the floor so that the sinking of the tub assembly into the cabinet (1) due to the weight of the washing water taken into the tub (2) during the operation of the washing machine and consequently the differentiation between the centers of the drum (3) rotational axis and the loading door will the prevented.
Yet another objective of the present invention is the use of elastic bands (6) being the subject matter of the invention, in the place of such suspension mechanism components as spring (4), damper (5) etc. without using them. In this way, it will be possible to reduce the size of the space required between the structure body (1) and the tub assembly due to the geometrical structures of the known suspension mechanism components; consequently, to reduce the total volume and weight of the machine; or with the same body (1) dimensions, to provide the utilisation of the gained extra volume for other purposes; to carry the production and installation procedures of the suspension mechanism in a more economical way than the conventional technique from the standpoint of cost and time.